This patent application pertains to devices for rotational molding of plastic articles and, more specifically, to devices that may be used for production of multi-colored articles with a drawing.
The subject of USSR patent no. 695,083, cl. B29C 41/04, 1976 had the capability of casting multi-colored articles with a drawing, but the number of allowed drawings was limited.
Khibnik's USSR patent no. 1,655,053, cl. B29C 41/04, 1991 disclosed a device similar to the present invention. That device is used to produce multi-colored plastic articles by rotary molding. A rotor is provided with a drive for its own rotation. Spindles (molds) are located along the rotor periphery, adapted to rotate around its axis. The spindles have gear wheels. A casting device is also provided, having disks with grooves connected to the molds by means of packings. Spindles (molds) periodically turn by means of a central gear wheel which interacts with the gear wheels of the molds. Bevelled gear wheels are installed on the shaft, adapted for engagement with two bevelled wheels loosely set on the mechanism transverse shaft. Two tooth half-couplings are disposed on the shaft, so that, by axis displacement, they can interact by turning with the bevel gear wheels' tooth half-couplings. A spring-loaded carriage, on the edge of which the protection is made, is in the shape of a tooth. A link rigidly connected with a transverse shaft can reciprocate from a pusher connected through a rocker with an eccentric. The eccentric is connected with a control handle. A drawing switch is supplied with an article drawing pattern, made in the shape of a gear wheel. The gear wheel is engaged with gear wheel installed on the eccentric.
The aforementioned device has the following drawbacks:
1. Low capacity, since the casting of melt of different colors can be done only serially. PA1 2. Small diversity of drawings. PA1 3. Impossibility of getting a ready-made article with a drawing. PA1 4. Impossibility of getting a drawing in the shape of a ring or a multi-colored spiral. PA1 5. Impossibility of getting a drawing with exact color zone separation.
It would therefore be advantageous to overcome all of these drawbacks in rotational plastic molding device.